Transfer of Glucose to Phenolic Steroids and Possible Physiological Role of the Glucosides

Publisher Summary Over the past fifteen years, a series of novel glycosides of the steroid estrogens have been isolated in laboratories from the urine and bile of rabbits and of humans. These have included 2-acetamido-2-deoxyglucosides and glucosides, and it has been shown that these sugars could be transferred in vivo from their respective uridine nucleotides to the steroids by liver microsomal preparations. Glucose and galactose can be transferred, under appropriate conditions, to OH-3 to form monoglycosides. The evidence for the involvement of a lipid intermediate in the synthesis of the steroid glucosides is as follows: (1) liver microsomes can form significant amounts of these compounds in the absence of added UDP-glucose and of detectable amounts of endogenous UDP-glucose and (2) the chloroform–methanol or chloroform–methanol–water extracts of rabbit or pig liver enhance the synthesis. The evidence that has been obtained indicates that the formation of the estrogen glucosides facilitates the passage of the steroid through the outer membrane of the liver cell.